1. Technical Field
The present invention relates to shading/brightness detecting technology and, particularly, relates to a shading detecting method and a shading detecting apparatus for a camera module.
2. Description of Related Art
Portable electronic devices with camera modules are a popular for taking photos. To meet market demand for portability, a camera module typically comprising a condensing lens and a light-receiving member (i.e., electronic image sensors) received in an image space of the lens requires manufacturing. However, even a minimal defect in a manufacture process, such as a nominal deformation of the condensing lens or a small deviation between the light-receiving member and an optical axis of the condensing lens, could cause shading (i.e., unequal brightness levels) on an image formed on the light receiving member. Since shading degrades an imaging quality of the camera module, determining whether the dimensions and intensity of the shading of the camera module are within an acceptable range is an important part of ensuring quality production.
Conventionally, testing for shading detection is usually carried out by a visual inspection. However, such an inspection is carried out under varying criteria, especially given the human element involved (e.g., variances in skill level and in standards of individual inspectors), and is an inefficient use of man-power and resources.
Therefore, it is desirable to provide a shading detecting method and a shading detecting apparatus for the camera module, which can overcome the abovementioned problems.